Field-Flow-Fractionation Cleaning via Reverse Flow
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Solution Overview
Problem
The field-flow-fractionation apparatus of a crossflow type often traps samples in the separation membrane, making it difficult to remove residual samples efficiently, leading to contamination in subsequent analyses due to the prolonged presence of trapped samples in the separation channel.
Innovation Solution
A field-flow-fractionation apparatus with a separation channel, a waste fluid chamber, a flow rate adjusting part, a fluid supply flow path, and a control part that supplies a carrier fluid at a higher flow rate than the setting after analysis is completed to create a backward flow from the waste fluid chamber to the separation channel, effectively removing adhering samples from the separation membrane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the carrier fluid continues to flow in the separation channel to remove trapped samples, then the sample removal process is extended, but the time required for cleaning increases significantly
Solution Approach 1:
The patent applies reverse flow by supplying carrier fluid to the waste fluid chamber from the opposite direction, causing the fluid to flow backward through the separation membrane from the waste fluid chamber side toward the separation channel side. This reverse flow effectively dislodges and removes trapped samples that cannot be eliminated by forward flow alone, resolving the contradiction between complete sample removal and extended cleaning time.
Solution Approach 2:
The patent implements periodic switching between forward flow and reverse flow modes. The control part alternates the flow direction multiple times during the cleaning process, creating periodic action that enhances sample removal efficiency. This periodic reversal prevents sample accumulation and reduces overall cleaning time compared to continuous forward flow.
2Manufacturing precision
If a semipermeable membrane with pores is used for separation, then fractionation of fine particles is achieved, but samples become trapped in the pores and are difficult to remove
Solution Approach 1:
The patent applies reverse flow by supplying carrier fluid to the waste fluid chamber from the opposite direction, causing the fluid to flow backward through the separation membrane from the waste fluid chamber side toward the separation channel side. This reverse flow effectively dislodges and removes trapped samples that cannot be eliminated by forward flow alone, resolving the contradiction between complete sample removal and extended cleaning time.
Solution Approach 2:
The patent changes the flow direction parameter by implementing reverse flow through the separation membrane. By switching from forward flow to reverse flow, the system alters the physical parameters of fluid movement, enabling trapped samples to be pushed out of the membrane pores in the opposite direction, thus facilitating easier sample removal while maintaining separation precision.
3Reliability
If trapped samples remain in the separation channel, then contamination of subsequent samples occurs, but increasing the carrier fluid flow rate increases system pressure
Solution Approach 1:
The patent applies reverse flow by supplying carrier fluid to the waste fluid chamber from the opposite direction, causing the fluid to flow backward through the separation membrane from the waste fluid chamber side toward the separation channel side. This reverse flow effectively dislodges and removes trapped samples that cannot be eliminated by forward flow alone, resolving the contradiction between complete sample removal and extended cleaning time.
Solution Approach 2:
The patent implements periodic switching between forward flow and reverse flow modes. The control part alternates the flow direction multiple times during the cleaning process, creating periodic action that enhances sample removal efficiency. This periodic reversal prevents sample accumulation and reduces overall cleaning time compared to continuous forward flow.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method efficiently removes residual samples from the separation channel, reducing contamination risks and enabling quicker preparation for subsequent analyses by utilizing a higher flow rate to dislodge and discharge trapped particles.
Implementation Method 1
One of the wall surfaces forming the separation channel is a semipermeable membrane with pores (referred to also as a separation membrane)
Implementation Method 2
When a carrier fluid introduced into the channel passes through the wall surface, a flow (cross flow) in a direction perpendicular to a forward flow (channel flow) flowing from an inlet port to an outlet port of the separation channel is generated
Implementation Method 3
The amount of discharge from the frit is controlled by a mass flow controller (MFC) provided on a discharge port side
Data Source
AI summary
Provided is a field-flow-fractionation apparatus that is configured to supply a carrier fluid to a waste fluid chamber through a fluid supply flow path at a flow rate higher than a set flow rate of a flow rate adjusting part at a timing between an end of analysis of a sample and a start of analysis of a subsequent sample, thereby forming a flow of the carrier fluid from the waste fluid chamber to the separation channel. Accordingly, the sample adhering to a separation membrane is separated from the separation membrane and is discharged from the outlet port.